Block-letter sign



Dec.. 27, 1927.

W. G. SHELTON BLOCK LETTER SIGN Filed Nov. 7, 1924 FLg. l

I www 2 Sheets-Sheet 1 22g J7 A,Z0

INVFNTOR z By tlorlwys,

Dec. 27, 1927.

- 1,654,350 W. G. SHELTON BLOCK LETTER SIGN Filed NOV. '7, 1924 2Sheets-Sheet 2 60 53 .56 .59 MWD/11 y lNvENTOR y;

Patented Dec. 27, 1927.

iiNiTEnf sTATEs PATENT onirica.

WILLIAM GEN TRY SHELTON, F NEW YORK, N Y., AASSIGiNOIR T0HALLIWELL-SHELTON ELECTRIC CORPORATION, OF NEW YORK, N. Y., ACORPORAZIJION" OF NEW YORK.

annex-LETTER sicav.V

application aiea November t, i924. serial No. 748,356.

This invention rela-testo improvements in illuminated signs of theblock-letter type, and l,aims to provide improvements therein.

'lille present invention-provides a blockl letter sign, adapted for useas a unit of a composite illuminated sign, in which the brilliantlighting effect of gas-conducting tubes (Geissler tubes or the like)-may be had by the use of apparatus which, (while l@ making use of highvoltages for producing a high potential difference on the4 electrodes ofthe tube or tubes) will not produce harmful or objectionable edects onthe human system, .and which will not violate laws and lregulationsgenerally established concerning 'ordinary lighting circuits (20-110-220volts for example) and apparatus used therewith. f

- rllhe invention further provides a device 'in which the eliiciency ishigh, and a good lighting eli'ect obtained with an expenditure of arelatively small amount of energy, better illumination being obtainedwith small high frequency currents than can be obtained 25 with currentsof lower frequencies, such as those of induction coils andy alternatingcurrent generators.

The 'invention further provides a blockletter sign having advantageousfeatures as regards the use and manufacture thereof.

An embodiment of the invention is illus-i trated in the accompanyingdrawings, in which l Fig. 1 is a face view thereof.; Fig. 2`is avertical section on line 2- 2,- Fig. 1; j

Fig. 3 -is a horizontal section on the line Fig( 4 is a front view withthe face o cover of the sign removed; j

Fig. 5 is a .diagram of the electrical parts and connections.

Referring to said drawings, numeral 10 designates ayrareedgas-conducting illumi. nating tube (such as a Geissler tube) andl 15 ameansfor generating high frequency current for illuminating said tube, asepa'- rate high frequency current generating means 15 being providedfor each letter .(or, tube 10 in the shape of a letter), the current foreach letter sign or tube thereby being small and notwithstanding thehigh voltages of such a generating means, having no objectionable ordangerous effect on the human system when a part thereof is brought intocontact with the high voltage part of the device. These signs, similarlyto the blockletter signs now in use having incandescent lamps, are usedwith others to form a composite sign, such as a wor-d or phrase. Currentfrom an ordinary lighting circuit (110 `or 220 volts) for energizing thehigh frequency current generating means 15, is taken through suitableleads 17, 18, and as the current used is much less than that used forblock-letter signs of the same size and lighting effect using filamentlamps, and as the high frequency high voltage current is not dangerous,the letter sign does not violate civil regulations relating to ordinarylighting circuits and attachments thereto.

The block-letter sign preferably comprises a box or casing 20, in whichthe high-frequency current generating means 15 is housed. rlhe casingpreferably has a cover 25 which closes the box or casing 20, and whichalso preferably serves for supporting the illuminating tube 10. Forprotecting the tube 10 and for. concentrating the light from said tube,a channel 27 is preferably formed on said cover 25'. This channel hasvthe outline of a. letter of the alphabet corresponding to the shape ofthe illuminating tube 10, and is conveniently formed by a flange 28,standing up from the face of said cover. The cover yis preferably cutout at the bottom of said channel, as indicated at 29.4 A plate ofinsulating material 33 (such as sheet asbestos) is preferably arrangedbehind the face' of said cover 25 andthe illuminating tube 10 isconveniently fastened thereto, as by means of straps 35. The plate 33 isconveniently held between flanges 37, 38

on the box and cover, one ofowhich has a down turned portion 39 to closethe `joint between said lianges. 'y

The tube 10 is bent to the shape of a letter ofthe alphabet, and asstated above, fits in the correspondingly shaped channel .27, and tothe' end that an equal illumination of all parts of the letter may beobtained in a convenient manner, the tube is bent into a double outlineof the letter. Thus'a continuous tube from end vto end, equallyoccupying all parts of the letter, and not crossing itself at any part,is attained. The tube consequently is able to lie flat against the late33, or otherl party ofmthe cover, and Hence may be well protected whenin a chanl nel such as 27 formed by the flanges 28. rll'he tube alsooccupies little space in a direction perpendicular to the face of theletter, in contrast to the space occupied by filament lamps. c

Any suitable high frequency current generating means 15 may be used.rlhe simple form here illustrated and adapted'for use with a lightingcircuit having either alternating or direct current, comprisesfone ortwo transformers 40, 41, to the secondary or secondaries 43 of which aterminal 45, or the terminals 45, 46 of the illuminating tube l0 areconnected (as by means of wires`48, Figs. 24). The primary or primaries50 of the transformer 4() or transformers 40, 41 are in an oscillatingcircuit comprising a condenser 55, and spark-gap ,56 having terminals58, 59. The condenser is charged through the spark-gap 56, as 58 ismovable to make and break a circuit through lead 17, kick coil 60,

terminals 58, 59 (when in contact) conductor primaries) 50 oftransformer 40, (or transformers 40,v 41) and' conductor 67 and branches68, 69 thereof to the other lead 18 connected to the lighting circuit.This movable ,terminal 58 of-the spark gap is in the magnetic inliuenceof the kick coil 60, and breaks the circuit at the spark gap 56 as soonas current begins tovflow in the circuit. The inductive kickof the coil60 resulting from the breaking of the circuit, chargesthe condenser 55with current at a relatively high voltage which when the sparkingpotential of the gap 56 is exceeded, results in a disruptive dischargeacross said spark gap 56, setting up high frequency oscillations fromsaid condenser 55, through the primary (or primaries) 50 of thetransformer 40 (or transformers 4'0, 41).` The secondary (orsecondaries) 43 respond with (similar high frequency `currents which areforced to flow tlirougli tlie illuminating tube 10, and therebyvilluminate the same. When the movable terminal 58 'of the spark gap,again makes contact with the terminal 59, a similar action to that justdescribed takes place, and another V'chain of high frequency condenseroscillationsJ takes place.

The removable terminal 58 is conveniently normally pressed against theterminal 59 by. means of an adjustable weight 70 and a pivoted lever v72having an arm 75 on whic the terminal 58 is carried. i v

Where two transformers 40, 41 are used they are connected so thatcurrent flows through the primaries thereof in opposite directions. Itwill be seen that the branch leads 17, 18 to a lighting cir-v cuit andin one of these leads a kick coil 60 is placed. One of the terminals ofthe heretofore explained the sign is safe to liandle, is simpleiiiconstruction, may be economically manufactured, and is well adaptedto stand the usage to which` these -signs are subjected.

.'lhe inventive ideas herein set forth may receive a variety ofstructural embodiments, and are not limited to the embodiment hereinspecifically shown and described. Y

What 1 -claimisz v 1. An illuminated letter unit of a compositeilluminated sign, each unit comprising a casing, a channel in the lshapeof a letter attached to said casing, an illuminating tube bent to theshape of a letter within said channel, means in said casing forgenerating a .high frequency current for illuminatingsaid tube, saidhigh frequency current being of al kind which does not shock thehuman'system,and leads to a-lighting circuit for supplying current to saidhigh frequency current generator, said casing comprising a box and acover, said box and cover con st ituting a weather-tight enclosure forsaid high frequency'generator, and said illuminating tube being mountedon said cover.

2. An illuminated letter unit of a composite illuminated sign, each unitcomprising a casing, a channel in the shape of a letter attached to saidcasing, an illuminating tube bent to the shape of a letter within saidchannel, means in said casing for generating hanged box, and a liangedcover, said flanges over-lapping to exclude weather, and said -a highfrequency ,current for illuminating lia box and cover constituting'aweather-tight enclosure for said high frequency generator,

and said illuminating tube being mountedv on said cover. c

3. An illuminated letter unit of'a composite illuminated sign, each unitcomprising a casing, a channel in the shape of a letter attached to saidcasing, an illuminating tube bent to the shape of a letter within saidchannel, means in said -casing for generating a high frequency currentfor illuminating said tube, said high frequency current being of a kindwhich does not Shock the human system, and leads to a light-circuit forsupplying current to said high frequency current generator, said casingl'comprsing a channeled part and a Hat plate beprising a flanged box anda tlan ed cover, hind said channeled part, adapted to be held saidflanges over-lapping to exclu e Weather between said channeled part andbox. l0 and said box and cover constituting a .ln Witness whereof, Ihave hereunto 5 Weather-tight enclosure for said high fre- Signed myname.` f

quency generator, and said illuminating tube v being mounted on saidcover, said cover com- WLLIAM GENTRY SHELTON.

